Foreign matter removal device, pellicle manufacturing device, pellicle manufacturing method, and pellicle

Abstract

In the present disclosure, a foreign matter removal device is provided with: a vacuum ultraviolet light generation unit that generates vacuum ultraviolet light; the irradiation container is used for irradiating the protective film with the vacuum ultraviolet light; and a gas supply unit that supplies an inert gas to the irradiation container. The irradiation container is provided with: an irradiation chamber provided with a gas supply port for supplying the inert gas and a gas discharge port for discharging the inert gas; a transmission part which is located at the boundary of the irradiation chamber and transmits the vacuum ultraviolet light; and a stage which is disposed in the irradiation chamber and on which the pellicle is placed. The gas supply part is connected to the gas supply port.

Description

Technical Field

[0001] The present disclosure relates to a foreign matter removal device, a pellicle assembly manufacturing device, a pellicle assembly manufacturing method, and a pellicle assembly. Background Art

[0002] The miniaturization of semiconductor integrated circuits is promoted by photolithography. In photolithography, a transparent substrate (hereinafter referred to as a "photomask") with a pattern formed on one side is used. In order to prevent foreign matter such as dust from adhering to the surface of the photomask, a protective film assembly is attached to the photomask.

[0003] On the other hand, Patent Document 1 describes an apparatus and a method for removing foreign matter by generating a pressure pulse in a gas using a pressure pulse laser.

[0004] Patent Document 2 describes an apparatus and a method for removing foreign matter from a film by generating an electric field near the film and vibrating the film.

[0005] Patent Document 1: International Publication No. 2021 / 073799

[0006] Patent Document 2: International Publication No. 2020 / 109152 Summary of the invention

[0007] Problems to be solved by the invention

[0008] During the manufacturing process of the pellicle assembly, many foreign objects may adhere to the pellicle. The foreign objects on the pellicle increase the absorption of radiation during the exposure of the substrate, resulting in the possibility of local hot spots on the pellicle that may damage the pellicle. Therefore, it is required to remove the foreign objects attached to the pellicle.

[0009] The present disclosure has been made in view of the above circumstances.

[0010] An embodiment of the present disclosure aims to provide a foreign matter removal device, a pellicle assembly manufacturing device, and a pellicle assembly manufacturing method that can prevent damage to the pellicle membrane and remove foreign matter attached to the pellicle membrane.

[0011] Another embodiment of the present disclosure is to provide a pellicle that can suppress a decrease in the yield of semiconductor mass production.

[0012] Means for solving problems

[0013] Means for solving the above-mentioned problems include the following embodiments.

[0014] <1> A foreign body removal device, comprising:

[0015] a vacuum ultraviolet light generating unit for generating vacuum ultraviolet light,

[0016] an irradiation container for irradiating the protective film with the vacuum ultraviolet light, and

[0017] a gas supply unit for supplying an inert gas to the irradiation container;

[0018] The irradiation container has an irradiation chamber, and a gas supply port for supplying the inert gas and a gas exhaust port for exhausting the inert gas are provided in the irradiation chamber;

[0019] The gas supply unit is connected to the gas supply port.

[0020] <2> As stated <1> The foreign matter removing device described herein further includes a transmission portion for transmitting the vacuum ultraviolet light at a boundary between the irradiation chamber and the vacuum ultraviolet light generating portion.

[0021] <3> As stated <1> or <2> The foreign matter removal device described herein further includes a stage disposed in the irradiation chamber and for placing the pellicle membrane.

[0022] <4> As stated <1> ~ <3> In the foreign matter removal device described in any one of the above, the inert gas contains nitrogen.

[0023] <5> As stated <1> ~ <4> The foreign matter removal device according to any one of the above, wherein the cumulative light intensity of the vacuum ultraviolet light is 0.1 J / cm 2 ~100J / cm 2 . .

[0024] <6> As stated <1> ~ <5> The foreign matter removal device according to any one of the preceding claims, wherein the illumination of the vacuum ultraviolet light is 5 mW / cm 2 ~100mW / cm 2 .

[0025] <7> As stated <3> The foreign matter removing device described in the invention further comprises a transmission portion for transmitting the vacuum ultraviolet light at a boundary between the irradiation chamber and the vacuum ultraviolet light generating portion.

[0026] The irradiation container further includes a distance adjustment portion that adjusts the distance between the transmission portion and the stage.

[0027] <8> As stated <1> ~ <7> In the foreign matter removal device described in any one of the above, the gas exhaust port is arranged at a position lower than the center of the irradiation chamber in the height direction of the irradiation chamber.

[0028] <9> As stated <8> In the foreign matter removal device described above, the gas supply port is arranged at a position higher than the center of the irradiation chamber in the height direction of the irradiation chamber.

[0029] <10> As stated <1> ~ <9> The foreign matter removal device according to any one of the above, wherein the irradiation chamber has two opposing walls.

[0030] The gas supply port is disposed on one of the two opposing wall portions.

[0031] The gas exhaust port is disposed on the other of the two opposing wall portions.

[0032] <11> A manufacturing device for a protective film assembly, comprising the <1> to <10> A foreign body removal device as described in any one of the above.

[0033] <12> A method for manufacturing a protective film, comprising:

[0034] supplying an inert gas into the irradiation chamber, and

[0035] In an inert gas atmosphere in an irradiation chamber, the protective film is irradiated with vacuum ultraviolet light;

[0036] In the irradiation chamber, the oxygen concentration in the inert gas atmosphere is 5 volume % or less.

[0037] <13> As stated <12> In the method for producing a pellicle membrane, the oxygen concentration in the irradiation chamber is 3 volume % or less.

[0038] <14> As stated <12> or <13> In the method for producing a pellicle membrane, the inert gas includes nitrogen.

[0039] <15> As stated <12> ~ <14> The method for producing a pellicle membrane according to any one of claims , wherein the flow rate of the inert gas is 10 L / min to 1000 L / min.

[0040] <16> As stated <12> ~ <15> The method for producing a protective film according to any one of the above, wherein the cumulative light intensity of the vacuum ultraviolet light is 0.1 J / cm 2 ~100.0J / cm 2 .

[0041] <17> As stated <12> ~ <16> The method for producing a protective film according to any one of the above, wherein the illuminance of the vacuum ultraviolet light is 5 mW / cm 2 ~100mW / cm 2 .

[0042] <18> As stated <12> ~ <17> The method for producing a pellicle membrane according to any one of claims 1 to 5, wherein the irradiation time of the vacuum ultraviolet light is 1 second to 30 minutes.

[0043] <19> As stated <12> ~ <18> The method for producing a protective film according to any one of the above, wherein the irradiation chamber has a transmission portion at a boundary of the irradiation chamber for transmitting the vacuum ultraviolet light.

[0044] The separation distance between the permeable portion and the protective membrane is 0.3 mm to 2.0 mm.

[0045] <20> As stated <12> ~ <19> The method for producing a pellicle assembly according to any one of claims 1 to 5, wherein the pellicle membrane has a thickness of 100 nm or less.

[0046] <21> A protective film assembly comprising:

[0047] Protective film assembly frame, and

[0048] a protective film supported on the protective film assembly frame;

[0049] The protective film has a film thickness of less than 100 nm,

[0050] The protective film contains foreign matter with a size of 1 μm to 5 μm,

[0051] The number of the foreign matter is 35 or less.

[0052] Effects of the Invention

[0053] According to one embodiment of the present disclosure, a foreign matter removal device, a pellicle assembly manufacturing device, and a pellicle assembly manufacturing method are provided that can prevent the occurrence of damage to the pellicle membrane and remove foreign matter attached to the pellicle membrane.

[0054] According to another embodiment of the present disclosure, a pellicle assembly capable of suppressing a decrease in the yield of semiconductor mass production is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] [ Figure 1 ] Figure 1 It is a cross-sectional view of the foreign matter removal device according to the first embodiment of the present disclosure.

[0056] [ Figure 2 ] Figure 2 It is a cross-sectional view of a foreign matter removal device according to a second embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] In the present disclosure, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the minimum value and the maximum value, respectively.

[0058] In the numerical range recorded in stages in the present disclosure, the upper limit or lower limit recorded in a certain numerical range can also be replaced by the upper limit or lower limit of the numerical range recorded in other stages. In the numerical range recorded in the present disclosure, the upper limit or lower limit recorded in a certain numerical range can also be replaced by the value shown in the embodiment.

[0059] In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.

[0060] In the present disclosure, when there are a plurality of substances corresponding to each component, the amount of each component means the total amount of the plurality of substances unless otherwise specified.

[0061] In the present disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process can be achieved.

[0062] (1) Foreign matter removal device

[0063] The foreign matter removal device disclosed in the present invention comprises: a VUV light generating unit for generating vacuum ultraviolet (VUV (Vacuum Ultra Violet; hereinafter referred to as VUV) light; an irradiation container for irradiating the protective film with the VUV light; and a gas supply unit for supplying an inert gas to the irradiation container. The irradiation container has an irradiation chamber, and a gas supply port for supplying the inert gas and a gas exhaust port for exhausting the inert gas are provided in the irradiation chamber. The gas supply unit is connected to the gas supply port.

[0064] In the present disclosure, “VUV light” refers to light having a wavelength of 100 nm to 200 nm, and may also refer to light having a wavelength of 160 nm to 180 nm.

[0065] In the present disclosure, the term “inert gas” refers to a gas that absorbs VUV light to convert the gas into radicals or ionizes the molecules of foreign matter attached to the pellicle membrane, thereby facilitating the removal of the gas.

[0066] Since the foreign matter removal device of the present disclosure has the above-described configuration, it is possible to prevent the pellicle membrane from being damaged and remove foreign matter adhering to the pellicle membrane.

[0067] This effect is presumed to be based on the following reasons, but the present invention is not limited thereto.

[0068] In the present disclosure, when the gas supply unit supplies an inert gas into the irradiation chamber, the gas in the irradiation chamber (such as the atmosphere, etc.) is discharged to the outside of the irradiation chamber through the gas exhaust port. As a result, most of the gas in the irradiation chamber is replaced with an inert gas, and the oxygen concentration in the irradiation chamber can be less than 5% by volume. It should be noted that the oxygen concentration of the atmosphere is about 21% by volume. If the VUV light generating unit generates VUV light, the VUV light is irradiated toward the protective film mounted on the stage through the transmission unit. Since VUV light has a short wavelength, it is easily absorbed by gas molecules (such as oxygen, etc.). When oxygen molecules absorb VUV light, active oxygen species (such as ozone, oxygen free radicals, etc.) are easily generated.

[0069] When VUV light is generated in an inert atmosphere with an oxygen concentration of 5% by volume or less in the irradiation chamber, the amount of active oxygen species (such as ozone, oxygen radicals, etc.) generated is reduced, thereby suppressing the film reduction of the pellicle membrane caused by active oxygen species.

[0070] On the other hand, by irradiating VUV light to the foreign matter and the protective film, the photoelectric effect is generated, and the foreign matter and the protective film are respectively charged with positive charges. The positively charged foreign matter is released from the protective film due to the repulsive force with the positively charged protective film. The circulating gas moves the released foreign matter. As a result, the foreign matter is discharged to the outside of the irradiation chamber from the gas exhaust port. In particular, the mass of small foreign matter is small. Therefore, it can be considered that small foreign matter is easily released from the protective film and easily discharged to the outside of the irradiation chamber from the gas exhaust port.

[0071] As a result, it is estimated that the foreign matter removal device of the present disclosure can remove foreign matter attached to the pellicle membrane while preventing the pellicle membrane from being damaged.

[0072] In the case of a pellicle assembly used in exposure using EUV (extreme ultraviolet) light as an exposure light source (hereinafter also referred to as "EUV light pellicle assembly"), the transmittance of EUV light is increased. Therefore, in the EUV light pellicle assembly, the thickness of the pellicle is very thin (for example, several nm to about 200 nm). Therefore, the foreign matter removal device disclosed in the present invention is suitable for removing foreign matter attached to the pellicle of the EUV pellicle assembly.

[0073] The shape and size of the foreign matter removal device are not particularly limited and can be appropriately adjusted according to the number and size of the VUV light generating unit, the irradiation container, and the gas supply unit. The foreign matter removal device can be a large device for mass production of pellicle modules or a small laboratory-grade device.

[0074] (1.1) Irradiation container

[0075] The foreign matter removal device disclosed in the present disclosure includes an irradiation container.

[0076] The number of irradiation containers is not particularly limited, and may be at least one, and may be appropriately adjusted according to the scale of the foreign matter removal apparatus. The size and shape of the irradiation container are not particularly limited, and may be appropriately selected according to the scale of the foreign matter removal apparatus.

[0077] (1.1.1) Irradiation room

[0078] The irradiation container has an irradiation chamber. Inside the irradiation chamber, the pellicle is irradiated with VUV light.

[0079] The number of irradiation chambers is not particularly limited, and may be at least one, and may be appropriately adjusted according to the scale of the foreign matter removal apparatus. The size and shape of the irradiation chamber are not particularly limited, and may be appropriately selected according to the scale of the foreign matter removal apparatus.

[0080] (1.1.1.1) Gas supply port and gas exhaust port

[0081] The irradiation chamber is provided with a gas supply port and a gas exhaust port. The gas supply port is used to supply an inert gas to the interior of the irradiation chamber. The gas exhaust port is used to exhaust the inert gas from the interior of the irradiation chamber. Thus, the oxygen concentration in the irradiation chamber can be adjusted to within a desired range, and foreign matter attached to the protective film can be discharged to the outside of the irradiation chamber, which can further reduce foreign matter on the protective film. Furthermore, the pressure rise in the irradiation chamber caused by the supply of the inert gas can be suppressed. As a result, the durability of the irradiation chamber is improved.

[0082] The gas supply port is connected to the gas supply unit. The details of the gas supply unit will be described later. The gas discharge port may be connected to a known gas recovery device or may not be connected to a known gas recovery device. When the gas discharge port is not connected to the gas recovery device, the gas discharge port may be open to the atmosphere.

[0083] The number of the gas supply ports and the gas exhaust ports is not particularly limited, and may be at least one, and may be appropriately adjusted according to the size of the irradiation chamber and the like.

[0084] The arrangement positions of the gas supply port and the gas exhaust port are not particularly limited, and may be appropriately adjusted according to the size of the irradiation chamber and the like.

[0085] The gas exhaust port is preferably arranged at a position lower than the height of the center of the irradiation chamber (i.e., the center of the irradiation chamber in the direction of gravity) in the height direction of the irradiation chamber. Thus, it is easy to discharge the removed foreign matter out of the irradiation container. As a result, when the treated pellicle is handled, the occurrence of re-contamination caused by foreign matter accumulated in the irradiation container can be suppressed.

[0086] When the gas exhaust port is arranged at a position lower than the center of the irradiation chamber in the height direction of the irradiation chamber, it is preferred that the gas supply port is arranged at a position higher than the center of the irradiation chamber (i.e., the central part of the irradiation chamber in the gravity direction) in the height direction of the irradiation chamber (i.e., the gravity direction). As a result, the gas supplied from the gas supply port is easily evenly dispersed in the irradiation container. As a result, the foreign matter removal device of the present disclosure easily exhibits the target effect (film rupture suppression and foreign matter removal).

[0087] Preferably, the irradiation chamber has two opposing walls, a gas supply port is arranged on one of the two opposing walls, and a gas exhaust port is arranged on the other of the two opposing walls. Thus, the foreign matter removal device can more efficiently adjust the oxygen concentration in the irradiation chamber and can more efficiently discharge the foreign matter separated from the protective film to the outside of the irradiation chamber. The height of the gas exhaust port is preferably arranged at a position higher than the middle of the height of the irradiation chamber, and more preferably arranged at the upper part of the irradiation chamber. Thus, it becomes easy to suppress the attachment of foreign matter to the protective film assembly due to the rolling up of foreign matter accumulated on the bottom plate of the irradiation chamber. In order to easily discharge foreign matter accumulated on the bottom plate of the irradiation chamber to the outside of the irradiation chamber, the height of the gas exhaust port is preferably arranged at a position lower than the middle of the height of the irradiation chamber. In order to easily discharge foreign matter accumulated on the bottom plate of the irradiation chamber to the outside of the irradiation chamber and to make it difficult for foreign matter accumulated on the bottom plate of the irradiation chamber to be rolled up, it is preferred that the gas exhaust port is arranged at a position higher than the middle of the height of the irradiation chamber and a position lower than the middle of the height of the irradiation chamber.

[0088] When one main surface of the protective film is arranged opposite to the carrier described later, the gas supply port is preferably arranged so that the traveling direction of the inert gas immediately after being ejected from the gas supply port is orthogonal to the direction perpendicular to the main surface of the protective film on the side opposite to the carrier side (hereinafter also referred to as "surface"). As a result, the inert gas supplied from the gas supply port to the surface of the protective film is not likely to exert excessive force on the surface of the protective film. As a result, the occurrence of film rupture of the protective film can be suppressed.

[0089] The angle of the direction perpendicular to the surface of the protective film is not limited as long as it can suppress excessive force on the surface of the protective film. The angle of the direction perpendicular to the surface of the protective film can be, for example, in the range of 85° to 95° relative to the direction of travel of the inert gas just after it is ejected from the gas supply port. For the same reason, the gas outlet is preferably set so that the direction of travel of the inert gas just before entering the gas outlet is perpendicular to the direction perpendicular to the surface of the protective film.

[0090] (1.1.1.2) Transparent part

[0091] The foreign matter removal device disclosed in the present invention preferably further has a transparent portion that allows vacuum ultraviolet light to pass through at the boundary between the irradiation chamber and the vacuum ultraviolet light generating portion. The transparent portion may be provided on the irradiation chamber side, or may be provided in the irradiation chamber. In other words, the transparent portion may be a part of the wall portion constituting the irradiation chamber, or may be a member different from the wall portion constituting the irradiation chamber, such as a part of the irradiation container. The shape of the transparent portion is not particularly limited, and may be flat. The size and thickness of the transparent portion are not particularly limited, and may be appropriately selected according to the size and number of protective films arranged in the irradiation chamber. The material of the transparent portion can be any material that transmits VUV light, for example, quartz, magnesium fluoride (MgF2), calcium fluoride (CaF2), lithium fluoride (LiF), etc.

[0092] (1.1.1.3) Other wall parts

[0093] In addition to the transparent portion, the irradiation chamber may also have a plurality of other wall portions. The transparent portion and the plurality of other wall portions constitute an internal space for irradiating the protective film with VUV light. The volume and structure of the internal space are not particularly limited, and can be appropriately adjusted according to the size and number of protective films arranged in the irradiation chamber. The material of the other wall portions can be any material that is not easily corroded by VUV light, for example, metals, ceramics, etc. As metals, for example, aluminum, iron, copper, nickel, gold, silver, platinum, cobalt, zinc, lead, tin, titanium, chromium, magnesium, manganese and their alloys (stainless steel, brass, phosphor bronze, etc.) can be mentioned. Among them, from the viewpoint of excellent durability, the material of the other wall portions preferably contains aluminum, preferably aluminum.

[0094] The irradiation chamber may include a gas concentration meter, which measures the concentration of the inert gas and the oxygen concentration in the irradiation chamber.

[0095] (1.1.2) Carrier

[0096] The foreign matter removal device disclosed in the present invention preferably further has a carrier disposed in the irradiation chamber and used to carry the protective film. The protective film is carried on the carrier. A protective film assembly having a protective film may also be carried on the carrier. In the case where the protective film is carried on the carrier, a carrier for the protective film with the protective film mounted thereon may also be carried on the carrier. The carrier for the protective film is, for example, a clamp for conveying the protective film. In the case where the protective film assembly is carried on the carrier, a carrier for the protective film assembly with the protective film assembly mounted thereon may also be carried on the carrier. The carrier for the protective film assembly is, for example, a clamp for conveying the protective film assembly. Details of the protective film assembly will be described later.

[0097] The number of carriers is not particularly limited, and can be at least one, and can be appropriately adjusted according to the scale of the foreign matter removal device. The number of carriers can be one or more than two per irradiation chamber. It can also be a movable carrier such as a belt conveyor.

[0098] The shape of the stage is not particularly limited as long as it can carry the pellicle, and can be appropriately selected according to the size and number of pellicles arranged in the irradiation chamber. The material of the stage is not particularly limited, and the same materials as those exemplified as the materials of the other wall portions can be cited. Among them, from the viewpoint of excellent durability, the material of the stage preferably includes aluminum, preferably aluminum.

[0099] (1.1.3) Distance adjustment unit

[0100] When the foreign matter removal device disclosed in the present invention further has a transparent portion that allows the vacuum ultraviolet light to pass through at the boundary between the irradiation chamber and the vacuum ultraviolet light generating portion, the irradiation container preferably further has a distance adjustment portion. The distance adjustment portion adjusts the distance between the transparent portion and the carrier. Thus, the distance between the transparent portion and the protective film placed on the carrier (hereinafter also referred to as "irradiation distance") can be adjusted to a desired distance. As a result, the foreign matter removal device can efficiently remove foreign matter attached to the protective film.

[0101] The irradiation distance is preferably 0.3 mm to 2.0 mm. As a result, VUV light is less likely to be absorbed by molecules between the transmission portion and the distance adjustment portion. That is, the protective film is easily irradiated by VUV light, and the foreign matter to be removed is easily removed from the protective film. As a result, foreign matter attached to the protective film is more easily removed.

[0102] The irradiation distance is more preferably 0.4 mm or more, and further preferably 0.5 mm or more. The irradiation distance is more preferably 1.8 mm or less, further preferably 1.6 mm or less, and particularly preferably 1.4 mm or less.

[0103] The mechanism for adjusting the distance between the transparent portion and the stage is not particularly limited, and any known mechanism may be used, for example, a stacking mechanism. In the stacking mechanism, the distance between the transparent portion and the stage is adjusted by stacking thin plates. The thickness of the plate is, for example, 1 mm. The material of the distance adjusting portion is not particularly limited, and the same materials as those exemplified as the materials of the other wall portions may be used. Among them, from the viewpoint of excellent durability, the material of the distance adjusting portion preferably includes aluminum, preferably aluminum.

[0104] In order to more easily remove foreign matter attached to the protective film, an insulating layer may also be configured on the carrier of the present invention. That is, an insulating layer may also be provided between the carrier and the protective film assembly placed on the carrier. In order to prevent the protective film from being damaged and remove foreign matter attached to the protective film at the same time, the type of insulating layer (materials with different volume resistivities) may also be selected, or the thickness of the insulating layer may be adjusted. Glass, resin, etc. may be used as the insulating layer.

[0105] (1.2) VUV light generating unit

[0106] The foreign matter removal device disclosed in the present invention includes a VUV light generating unit. The VUV light generating unit generates VUV light. Specifically, the VUV light generating unit irradiates the pellicle placed on the stage with the VUV light via the transmission unit.

[0107] The number of VUV light generating units is not particularly limited, and can be at least one, and can be appropriately adjusted according to the scale of the foreign matter removal device. The number of VUV light generating units can be one or more than two relative to one irradiation chamber. The size and shape of the VUV light generating unit are not particularly limited, and can be appropriately selected according to the scale of the foreign matter removal device.

[0108] The VUV light generating unit may be any known light emitting device that generates VUV light.

[0109] The VUV light generating unit may also include a light source having a main emission wavelength of 100 nm to 200 nm (hereinafter, also referred to as a "light source"). The light source may be appropriately selected according to the type of inert gas supplied to the irradiation chamber, for example, a xenon (Xe) excimer lamp (main emission wavelength: 172 nm), a low-pressure mercury lamp (main emission wavelength: 185 nm), etc. Among them, the light source is preferably a Xe excimer lamp from the viewpoint of being able to radiate ultraviolet light of 172 nm at a single wavelength and having excellent luminous efficiency.

[0110] The cumulative amount of VUV light is preferably 0.1 J / cm 2 ~100J / cm 2 Thus, the foreign matter removal device can remove foreign matter while suppressing the occurrence of rupture of the protective film. The cumulative light intensity of the VUV light is more preferably 0.5 J / cm 2 More preferably, 1.0 J / cm 2 Above, particularly preferably 1.5 J / cm 2 The cumulative amount of VUV light is more preferably 70 J / cm 2 Below, more preferably 50 J / cm 2 Below, particularly preferably 30 J / cm 2 Below, more preferably 10 J / cm 2 the following.

[0111] The illuminance of VUV light is not particularly limited, but is preferably 5 mW / cm 2 ~100mW / cm 2 This can suppress the occurrence of rupture of the pellicle membrane and remove foreign matter.

[0112] In order to easily remove foreign matter in a short time, the illuminance of VUV light is more preferably 10 mW / cm 2More preferably, 20 mW / cm 2 Above, particularly preferably 30 mW / cm 2 In order to easily suppress the rupture of the protective film, the illumination of the VUV light is more preferably 70 mW / cm 2 Below, more preferably 66mW / cm 2 Below, particularly preferably 60 mW / cm 2 Therefore, the illuminance of VUV light is preferably 10 mW / cm 2 Above and 100mW / cm 2 , more preferably 20 mW / cm 2 Above 70mW / cm 2 Below, more preferably 30 mW / cm 2 Above 70mW / cm 2 the following.

[0113] (1.3) Gas supply unit

[0114] The foreign matter removal device disclosed in the present invention includes a gas supply unit. The gas supply unit supplies an inert gas to the irradiation container. Specifically, the gas supply unit supplies the inert gas to the irradiation chamber via a gas supply port.

[0115] The number of gas supply parts is not particularly limited, and it can be at least one, and it can be appropriately adjusted according to the scale of the foreign matter removal device. The number of gas supply parts can be one for one irradiation chamber, or it can be more than two. The gas supply part can also be one for multiple irradiation chambers. The size and shape of the gas supply part are not particularly limited, and can be appropriately selected according to the scale of the foreign matter removal device.

[0116] Examples of the inert gas include nitrogen (N2) gas, xenon (Xe) gas, and carbon dioxide (CO2) gas. The inert gas is preferably at least one selected from the group consisting of nitrogen (N2) gas, xenon (Xe) gas, and carbon dioxide (CO2) gas. Among them, from the viewpoint of efficiently removing foreign matter attached to the protective film, the inert gas more preferably includes nitrogen gas, and nitrogen gas is particularly preferred.

[0117] The gas supply unit may be any known gas supply device that supplies an inert gas. The gas supply unit may include a flow meter.

[0118] (1.4) First Implementation Method

[0119] Below, refer to Figure 1 A foreign matter removal device according to a first embodiment of the present disclosure will be described. Figure 1 In the diagram, the symbol "G" indicates the direction of gravity.

[0120] like Figure 1 As shown, the foreign matter removal apparatus 1000A includes one irradiation container 1A, one VUV light generator 2, and one gas supply unit 3. The VUV light generator 2 and the gas supply unit 3 are each mounted in the irradiation container 1A.

[0121] (1.4.1) Irradiation container

[0122] The irradiation container 1A has one irradiation chamber 10A. The irradiation chamber 10A has an internal space R inside. The internal space R is a substantially rectangular parallelepiped. For example, it is 300 cm 3 ~600000cm 3 , can also be 5000cm 3 ~200000cm 3 .

[0123] (1.4.1.1) Irradiation room

[0124] The irradiation chamber 10A further includes an upper wall 100a, a right wall 100b, a lower wall 100c, a left wall 100d, a front wall (not shown), and a rear wall (not shown). The upper wall 100a is opposite to the lower wall 100c. The right wall 100b is opposite to the left wall 100d. The front wall is opposite to the rear wall. The upper wall 100a, the right wall 100b, the lower wall 100c, the left wall 100d, the front wall, and the rear wall constitute an internal space R. The upper wall 100a, the right wall 100b, the lower wall 100c, the left wall 100d, the front wall, and the rear wall are each made of aluminum.

[0125] The upper wall 100a has a transmissive portion 101. The transmissive portion 101 constitutes a part of the upper wall 100a. The transmissive portion 101 is a square flat plate. The transmissive portion 101 is made of quartz. The VUV light generating unit 2 is arranged on the surface of the transmissive portion 101 opposite to the internal space R.

[0126] The right wall portion 100b has a gas exhaust port 102. The gas exhaust port 102 communicates with the internal space R. The gas exhaust port 102 is open to the atmosphere.

[0127] The left wall portion 100 d has a gas supply port 103 . The gas supply port 103 communicates with the internal space R. The gas supply port 103 is connected to the gas supply unit 3 .

[0128] The irradiation chamber 10A includes a gas concentration meter 104. The gas concentration meter 104 is disposed in the internal space R. The gas concentration meter 104 is a well-known gas concentration meter.

[0129] The irradiation container 1A further includes a distance adjusting portion 11 and a stage 12 . The distance adjusting portion 11 and the stage 12 are arranged in the internal space R. Specifically, the distance adjusting portion 11 is attached to the lower wall portion 100 c . The stage 12 is attached to the distance adjusting portion 11 .

[0130] The distance adjusting unit 11 is a stacking unit. The material of the member constituting the distance adjusting unit 11 is aluminum. In the present embodiment, the distance adjusting unit is adjusted so that the irradiation distance H becomes 1.0 mm.

[0131] The stage 12 is a square flat plate. The material of the stage 12 is aluminum. On the stage 12, a pellicle assembly 2000 having a pellicle membrane is placed.

[0132] (1.4.2) VUV light generating unit

[0133] The VUV light generating unit 2 is a known light emitting device that generates VUV light L. In this embodiment, the known light emitting device includes a xenon (Xe) excimer lamp. The xenon (Xe) excimer lamp radiates 172nm ultraviolet light. The cumulative light amount of the VUV light is 0.1J / cm 2 ~100J / cm 2 .

[0134] (1.4.3) Gas supply unit

[0135] The gas supply unit 3 is a well-known gas supply device that supplies an inert gas F. In the present embodiment, the inert gas F is nitrogen (N2) gas.

[0136] (1.4.4) Effects

[0137] As reference Figure 1 As explained, Figure 1 As shown, the foreign matter removal device 1000A includes an irradiation container 1A, a VUV light generator 2, and a gas supply unit 3. The VUV light generator 2 and the gas supply unit 3 are respectively installed in the irradiation container 1A. The irradiation container 1A has an irradiation chamber 10A provided with a gas supply port 103 and a gas exhaust port 102, and a stage 12. The irradiation chamber 10A has a transmission portion 101. The gas supply unit 3 is connected to the gas supply port 103.

[0138] Thus, foreign matter removal apparatus 1000A can irradiate the pellicle membrane included in pellicle assembly 2000 with VUV light L in an inert atmosphere with an oxygen concentration of 5 vol% or less in irradiation chamber 10A. As a result, foreign matter removal apparatus 1000A can prevent the pellicle membrane from being damaged and remove foreign matter attached to the pellicle membrane.

[0139] As reference Figure 1As described above, the inert gas F includes nitrogen. Thus, the foreign matter removal apparatus 1000A can efficiently remove foreign matter attached to the pellicle membrane.

[0140] As reference Figure 1 As explained above, the cumulative amount of VUV light L is 0.1 J / cm 2 ~100J / cm 2 The foreign matter removal apparatus 1000A can remove foreign matter while suppressing the occurrence of rupture of the pellicle membrane.

[0141] As reference Figure 1 As described above, the irradiation container 1A further includes the distance adjustment unit 11. This allows the irradiation distance H to be adjusted to a desired distance. As a result, the foreign matter removal apparatus 1000A can efficiently remove foreign matter attached to the pellicle membrane.

[0142] (1.5) Second Implementation

[0143] Below, refer to Figure 2 A foreign matter removal device according to a second embodiment of the present disclosure will be described.

[0144] The foreign matter removal apparatus 1000B has the same configuration as the foreign matter removal apparatus 1000A, except that the transmission portion 101 is not a part of the upper wall portion 100a constituting the irradiation chamber 10A.

[0145] like Figure 2 As shown, the foreign matter removal apparatus 1000B includes an irradiation container 1B, a VUV light generating unit 2 , and a gas supply unit 3 .

[0146] The irradiation chamber 10A has a transmission portion 101. The transmission portion 101 is attached to a rear wall portion (not shown).

[0147] Since the foreign matter removal device 1000B has the above-mentioned structure, it can achieve the same effects as the foreign matter removal device 1000A.

[0148] (2) Protective membrane assembly manufacturing device

[0149] The pellicle assembly manufacturing apparatus of the present disclosure includes the foreign matter removing apparatus of the present disclosure.

[0150] Since the pellicle assembly manufacturing apparatus of the present disclosure has the above-described configuration, it is possible to prevent the pellicle from being damaged and remove foreign matter adhering to the pellicle.

[0151] This effect is presumably due to the same reason as the effect of the foreign matter removal device of the present disclosure, but the present invention is not limited thereto.

[0152] The pellicle assembly manufacturing apparatus of the present disclosure may include a known pellicle assembly manufacturing apparatus, such as the pellicle assembly manufacturing apparatus described in International Publication No. 2015 / 182483 and the pellicle assembly mounting apparatus described in International Publication No. 2015 / 182482.

[0153] (3) Protective film assembly

[0154] The pellicle assembly disclosed herein comprises a pellicle assembly frame and a pellicle membrane supported on the pellicle assembly frame. The pellicle membrane has a film thickness of 100 nm or less. The pellicle membrane contains foreign matter of 1 μm to 5 μm in size. The number of the foreign matter is 35 or less.

[0155] Since the pellicle of the present disclosure has the above-described configuration, it is possible to suppress a decrease in the yield rate of semiconductor mass production.

[0156] This effect is presumed to be based on the following reasons, but the present invention is not limited thereto.

[0157] The number of foreign matter is 35 or less, indicating that the number of foreign matter attached to the protective film is very small. If the protective film assembly of the present invention is used, the number of foreign matter that moves from the protective film to the photomask during the exposure process is small. Therefore, it is more difficult for the yield ratio of semiconductor mass production to decrease. As a result, the protective film assembly of the present invention can suppress the decrease in the yield rate of semiconductor mass production.

[0158] The number of foreign matter is not more than 35. In particular, the closer the number of foreign matter is to 0, the more preferable it is, and 0 is most preferable.

[0159] The number of foreign matter is 35 or less, preferably 30 or less, and more preferably 15 or less. The number of foreign matter may be 5. The number of foreign matter may be 5 to 35. In particular, the closer the number of foreign matter is to 0 or less, the more preferable.

[0160] The method for measuring the number of foreign matter is the same as that described in Examples.

[0161] The method of reducing the number of foreign matter to 35 or less includes, for example, a method of subjecting the pellicle membrane to the method for producing the pellicle membrane of the present disclosure, which will be described later.

[0162] (3.1) Protective film assembly frame

[0163] The pellicle membrane of the present disclosure includes a pellicle assembly frame. The pellicle assembly frame supports the pellicle membrane.

[0164] The pellicle assembly frame may be a rectangular cylindrical object consisting of two long sides and two short sides. The pellicle assembly frame has a through hole. The through hole indicates a space through which the exposure light passing through the pellicle passes to reach the photomask.

[0165] The pellicle assembly frame may also have a vent. The vent connects the internal space of the pellicle assembly with the external space of the pellicle assembly when the pellicle assembly frame is attached to the photomask. The "internal space of the pellicle assembly" refers to the space surrounded by the pellicle assembly and the photomask. The "external space of the pellicle assembly" refers to the space not surrounded by the pellicle assembly and the photomask.

[0166] Examples of materials for the pellicle assembly frame include aluminum, titanium, stainless steel, carbon-based materials, ceramic-based materials (such as silicon, glass, etc.), and resins such as polyethylene. The pellicle assembly frame is preferably made of aluminum, titanium, or silicon, more preferably silicon. The pellicle assembly frame may also be a laminated structure of multiple materials.

[0167] The shape of the pellicle frame corresponds to the shape of the photomask. Examples of the shape of the pellicle frame include a rectangular frame shape and a square frame shape.

[0168] (3.2) Protective film

[0169] The pellicle assembly disclosed in the present invention includes a pellicle. The pellicle prevents foreign matter from adhering to the surface of the photomask and allows exposure light to pass through during exposure. Foreign matter includes dust. Examples of exposure light include deep ultraviolet (DUV) light, EUV light, and the like.

[0170] The pellicle membrane covers the entire opening of one end surface side of the through hole of the pellicle membrane assembly frame. The pellicle membrane can be directly supported on one end surface of the pellicle membrane assembly frame, or can be supported via a membrane adhesive layer. The membrane adhesive layer can be a cured product of a known adhesive.

[0171] The film thickness of the pellicle membrane is 100 nm or less, preferably 1 nm to 100 nm, more preferably 2 nm to 100 nm or less, and even more preferably 3 nm to 70 nm.

[0172] The rectangular pellicle assembly frame is composed of four sides when viewed in the thickness direction.

[0173] The length of one side in the longitudinal direction is preferably 200 mm or less. The dimensions of the pellicle assembly frame and the like are standardized according to the type of exposure apparatus. When the length of one side of the pellicle assembly frame in the longitudinal direction is 200 mm or less, the standardized dimensions for exposure using EUV light are satisfied.

[0174] The length of one side in the short-side direction can be, for example, 5 mm to 180 mm, preferably 80 mm to 170 mm, and more preferably 100 mm to 160 mm.

[0175] The height of the pellicle assembly frame (i.e., the length of the pellicle assembly frame in the thickness direction) is not particularly limited, but is preferably 3.0 mm or less, more preferably 2.4 mm or less, and further preferably 2.375 mm or less. Thus, the pellicle assembly frame satisfies the dimensions standardized for EUV exposure. The height of the pellicle assembly frame standardized for EUV exposure is, for example, 2.375 mm.

[0176] The mass of the pellicle frame is not particularly limited, but is preferably 20 g or less, and more preferably 15 g or less. Thus, the pellicle frame is suitable for EUV exposure applications.

[0177] As a protective film, there is no particular limitation, for example, polycrystalline silicon (P-Si) film, silicon nitride (SiN) film, silicon carbide (SiC) film, metal silicide film, carbon nanotube film, graphene film, etc. can be cited, among which the protective film is preferably polycrystalline silicon (P-Si) film, silicon nitride (SiN) film, silicon carbide (SiC) film, metal silicide film (such as molybdenum silicide film, etc.), carbon nanotube film, or graphene film. The protective film is further preferably polycrystalline silicon (P-Si) film, silicon nitride (SiN) film, silicon carbide (SiC) film, metal silicide film or carbon nanotube film, and is further preferably polycrystalline silicon (P-Si) film, molybdenum silicide film or carbon nanotube film. The carbon nanotube film can be a single-walled carbon nanotube, or a multi-walled carbon nanotube, or it can contain single-walled carbon nanotubes and multi-walled carbon nanotubes.

[0178] (3.3) Adhesive layer

[0179] The pellicle assembly of the present disclosure may or may not further include an adhesive layer. The adhesive layer enables the pellicle assembly of the present disclosure to be bonded to a photomask.

[0180] The adhesive layer is a gel-like viscoelastic body. The adhesive layer has viscosity and cohesion. Viscosity refers to the property of a liquid that comes into contact with and wets the photomask as an adherend. Cohesion refers to the property of a solid that resists peeling from the photomask.

[0181] As described later, the adhesive layer is formed by applying the coating composition, heating, drying, curing, and the like.

[0182] The adhesive composition is not particularly limited, and may be a known adhesive, such as an acrylic adhesive, a silicone adhesive, a styrene butadiene adhesive, a urethane adhesive, an olefin adhesive, and the like.

[0183] (3.4) Gasket

[0184] When the pellicle assembly of the present disclosure further includes an adhesive layer, it may or may not further include a liner (release film).

[0185] The liner protects at least the surface of the adhesive layer that contacts the photomask. The liner can be peeled off from the adhesive layer.

[0186] (4) Method for manufacturing protective film

[0187] The method for manufacturing a protective film disclosed in the present invention includes: supplying an inert gas into an irradiation chamber (hereinafter also referred to as a "gas supply process"); and irradiating the protective film with VUV light under the inert gas atmosphere in the irradiation chamber (hereinafter also referred to as an "irradiation process"). The irradiation of the VUV light and the supply of the inert gas may be performed simultaneously or at different times. The inert gas atmosphere may contain no oxygen or may contain oxygen. When the oxygen is contained in the irradiation chamber, the concentration is 5% by volume or less.

[0188] The pellicle manufacturing method disclosed herein has the above-mentioned structure, so it is possible to prevent the pellicle from being damaged and remove foreign matter attached to the pellicle. Specifically, if the pellicle manufacturing method disclosed herein is used for a pellicle assembly having a pellicle with foreign matter attached thereto, the pellicle assembly disclosed herein can be obtained.

[0189] This effect is presumably due to the same reason as the effect of the foreign matter removal device of the present disclosure, but the present invention is not limited thereto.

[0190] (4.1) Device

[0191] The pellicle membrane manufacturing method may be implemented using the foreign matter removal apparatus disclosed herein or may not be implemented using the foreign matter removal apparatus disclosed herein. From the viewpoint of efficiently implementing the pellicle membrane manufacturing method, etc., the pellicle membrane manufacturing method is preferably implemented using the foreign matter removal apparatus disclosed herein.

[0192] (4.1.1) Irradiation room

[0193] The irradiation chamber may be any chamber that has a function of irradiating the pellicle with VUV light and reducing the oxygen concentration to 5 vol % or less, and examples thereof include the irradiation chamber in the foreign matter removal apparatus of the present disclosure.

[0194] It is preferred that the irradiation chamber has a transmissive portion for transmitting VUV light at the boundary of the irradiation chamber, and the distance between the transmissive portion and the pellicle is 0.3 mm to 2.0 mm. If the irradiation distance is within the range of 0.3 mm to 2.0 mm, VUV light can easily reach the pellicle, and foreign matter to be removed can be easily removed from the pellicle. As a result, foreign matter attached to the pellicle can be removed.

[0195] The irradiation distance is more preferably 0.4 mm or more, and further preferably 0.5 mm or more. The irradiation distance is more preferably 1.8 mm or less, further preferably 1.6 mm or less, and particularly preferably 1.4 mm or less.

[0196] The method for adjusting the irradiation distance to fall within the above range is not particularly limited, and examples thereof include a method of using the distance adjustment unit in the foreign matter removal device of the present disclosure.

[0197] (4.2) Gas supply process

[0198] The method for manufacturing a protective film includes a gas supply process. In the gas supply process, an inert gas is supplied to the irradiation chamber. As a result, most of the gas in the irradiation chamber can be replaced with an inert gas. In other words, the irradiation chamber can be an inert gas atmosphere. As a result, the oxygen concentration in the irradiation chamber can be zero (0 volume %), and in the case of containing oxygen, the oxygen flows in from outside the irradiation chamber, etc., it can also be set to a range of less than 5 volume %.

[0199] The method of supplying the inert gas into the irradiation chamber is not particularly limited, and examples thereof include a method using the gas supply unit in the foreign matter removal apparatus of the present disclosure.

[0200] (4.2.1) Inert gas

[0201] The inert gas may be the same inert gas as the inert gas supplied by the gas supply unit of the foreign matter removal device of the present disclosure. From the viewpoint of efficiently removing foreign matter attached to the pellicle, the inert gas preferably includes nitrogen, and nitrogen is particularly preferred.

[0202] The flow rate of the inert gas is not particularly limited, but is preferably 10 L / min or more. If the flow rate of the inert gas is 10 L / min or more, the removed foreign matter can be discharged to the outside of the irradiation container, and the foreign matter can be easily removed from the protective film, preferably 50 L / min or more. There is no particular reason for the upper limit, for example, it can be 1000 L / min or less. From these viewpoints, the flow rate of the inert gas is preferably 10 L / min or more and 1000 L / min or less, and more preferably 30 L / min to 1000 L / min.

[0203] The flow rate of the inert gas is measured with a known flow meter.

[0204] (4.3) Irradiation process

[0205] The method for manufacturing the pellicle membrane includes an irradiation step. In the irradiation step, the pellicle membrane is irradiated with VUV light in a specific inert gas atmosphere in an irradiation chamber. This allows foreign matter attached to the pellicle membrane to be separated from the pellicle membrane.

[0206] The method of irradiating the pellicle membrane with VUV light is not particularly limited, and examples thereof include a method using the VUV light generating unit in the foreign matter removal apparatus of the present disclosure.

[0207] (4.3.1) Inert gas atmosphere

[0208] The inert gas atmosphere contains oxygen. The oxygen contained in the inert gas atmosphere may be oxygen that cannot be exhausted from the irradiation chamber even when the gas supply process is performed.

[0209] The oxygen concentration in the irradiation chamber is 5% by volume or less, preferably 3% by volume or less. When the oxygen concentration is 3% by volume or less, the film reduction and damage of the pellicle membrane can be further suppressed.

[0210] The oxygen concentration is not particularly limited, and may be 0.000 volume % or more, and may be 0.001 volume % or more, 0.005 volume % or more, or 0.10 volume % or more.

[0211] The oxygen concentration in the irradiation chamber is not particularly limited, but is preferably 2% by volume or less, further preferably 1% by volume or less, further preferably 0.8% by volume or less, further preferably 0.5% by volume or less, and particularly preferably 0.1% by volume or less, from the viewpoint of suppressing the occurrence of rupture of the protective film and removing foreign matter.

[0212] From these viewpoints, the oxygen concentration is preferably 0.000 to 5% by volume, more preferably 0.000 to 1% by volume, further preferably 0.001 to 0.8% by volume, particularly preferably 0.001 to 0.5% by volume, and still more preferably 0.001 to 0.1% by volume.

[0213] The oxygen concentration is measured using a known gas concentration meter.

[0214] The inert gas atmosphere may contain an active gas in addition to oxygen. The term "active gas" refers to a gas that reacts with the pellicle membrane and easily damages the pellicle membrane. The active gas contained in the inert gas atmosphere may be an active gas that cannot be exhausted from the irradiation chamber even if the gas supply process is performed.

[0215] Examples of the active gas include water (H 2 O), carbon monoxide (CO) gas, and hydrogen (H 2 ) gas.

[0216] (4.3.2) Irradiation

[0217] The cumulative amount of VUV light is not particularly limited, but is preferably 0.1 J / cm 2 ~100.0J / cm 2This can suppress the occurrence of rupture of the protective film and remove foreign matter. The cumulative light intensity of the VUV light is more preferably 0.5 J / cm 2 More preferably, 1.0 J / cm 2 Above, particularly preferably 1.5 J / cm 2 The cumulative amount of VUV light is more preferably 70 J / cm 2 Below, more preferably 50 J / cm 2 Below, particularly preferably 30 J / cm 2 Below, more preferably 10 J / cm 2 the following.

[0218] The illuminance of VUV light is not particularly limited, but is preferably 5 mW / cm 2 ~100mW / cm 2 This can suppress the occurrence of rupture of the pellicle membrane and remove foreign matter.

[0219] In order to easily remove foreign matter in a short time, the illuminance of VUV light is more preferably 10 mW / cm 2 More preferably, 20 mW / cm 2 Above, particularly preferably 30 mW / cm 2 In order to easily suppress the rupture of the protective film, the illumination of the VUV light is more preferably 70 mW / cm 2 Below, more preferably 66mW / cm 2 Below, particularly preferably 60 mW / cm 2 the following.

[0220] The irradiation time of VUV light is not particularly limited, but is preferably 1 second to 30 minutes. If the irradiation time of VUV light is 1 second or longer, it is easier to remove foreign matter. If the irradiation time of VUV light is within 30 minutes, the occurrence of rupture of the protective film can be further suppressed.

[0221] In the present disclosure, the gas supply process and the irradiation process may be performed simultaneously or not. When the gas supply process and the irradiation process are performed simultaneously, it is easier to irradiate the pellicle with VUV light while maintaining the oxygen concentration at 5% by volume or less than when the gas supply process and the irradiation process are not performed simultaneously. As a result, the occurrence of rupture of the pellicle can be further suppressed.

[0222] For example, in the irradiation chamber, the following operations may be performed at least once: starting supply of the inert gas, stopping supply of the inert gas, starting irradiation of the VUV light, and stopping irradiation of the VUV light in sequence.

[0223] (4.4) Protective film

[0224] In the method for manufacturing a pellicle assembly of the present disclosure, the pellicle membrane preferably has a thickness of 100 nm or less.

[0225] In the method for manufacturing a pellicle assembly disclosed herein, even if the pellicle has a thickness of 100 nm or less, it is possible to prevent the pellicle from being damaged and remove foreign matter attached to the pellicle. From the same viewpoint, the pellicle suitable for the method for manufacturing a pellicle assembly disclosed herein preferably has a thickness of 1 nm to 100 nm, more preferably 2 nm to 100 nm, and even more preferably 3 nm to 70 nm.

[0226] (4.5) Preparation process

[0227] The method for manufacturing a pellicle assembly of the present disclosure may include a step of preparing the pellicle assembly (hereinafter also referred to as a “preparation step”). When the method for manufacturing a pellicle assembly includes the preparation step, the method for removing foreign matter from a pellicle assembly of the present disclosure is performed after the preparation step.

[0228] The method for preparing the pellicle module is not particularly limited, and examples thereof include a method for producing the pellicle module and a method for obtaining a commercially available product.

[0229] The method for manufacturing the pellicle assembly is not particularly limited, as long as it is a known manufacturing method. As a known manufacturing method, for example, the manufacturing method of the pellicle assembly described in Japanese Patent Publication No. 2021-157058, Japanese Patent Publication No. 2020-166063, Japanese Patent Publication No. 2020-160345, International Publication No. 2019 / 240166, and Japanese Patent Publication No. 2019-174628 can be cited.

[0230] Example

[0231] Hereinafter, the present disclosure will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0232] [1] Example 1

[0233] [1.1] Preparation process

[0234] [1.1.1] Foreign matter removal device

[0235] Prepare Figure 1 The foreign body removal device 1000A is shown.

[0236] [1.2] Protective film assembly

[0237] As pellicle assembly 2000, a first pellicle assembly was produced as follows.

[0238] A polycrystalline silicon (p-Si) film of less than 100 nm is formed on a silicon substrate. Then, the silicon substrate is etched from the surface opposite to the surface on which the polycrystalline silicon (p-Si) film is formed to form a self-supporting film of the polycrystalline silicon (p-Si) film. "Self-supporting film" refers to an area in the polycrystalline silicon (p-Si) film that is not supported by the silicon substrate. Thus, a first protective film assembly is prepared.

[0239] The first pellicle assembly includes a first pellicle assembly frame obtained by etching a silicon substrate and a first pellicle membrane composed of a polysilicon (p-Si) film. The first pellicle membrane is supported by the first pellicle assembly frame. The dimensions of the first pellicle assembly are as follows.

[0240] Thickness of the first protective film: less than 100nm

[0241] Overall dimensions of the first pellicle assembly frame (outer diameter): 151.3 mm × 139.7 mm × 2.4 mm Dimensions of the first pellicle assembly frame (opening): 143.6 mm × 111.1 mm

[0242] In order to evaluate foreign matter, the foreign matter was spread on the pellicle membrane, and the first pellicle membrane assembly was placed on stage 12 in irradiation chamber 10A of irradiation container 1A. Irradiation distance H was adjusted to 1 mm.

[0243] [1.2] Gas supply process

[0244] The irradiation chamber 10A is sealed. An inert gas F (i.e., nitrogen (N2) gas) is supplied into the irradiation chamber 10A from the gas supply unit 3 at a gas supply rate of 50 L / min for 2 minutes and 30 seconds. After that, the supply of the inert gas F is not stopped and the inert gas F is continuously supplied into the irradiation chamber 10A. The nitrogen (N2) gas in the irradiation chamber 10A is discharged to the outside of the irradiation chamber 10A from the gas exhaust port 102.

[0245] The oxygen concentration and nitrogen concentration in the irradiation chamber 10A were measured by the gas concentration meter 104. The oxygen concentration was 0.6% by volume. The nitrogen concentration was 98% by volume or more. That is, it was found that the irradiation chamber 10A was an inert gas atmosphere.

[0246] [1.3] Irradiation process

[0247] The first pellicle membrane was irradiated with VUV light L (wavelength: 172 nm, illuminance: 33 mW / cm 2 ). Thus, an irradiated pellicle membrane assembly is obtained.

[0248] [2] Comparative Example 1

[0249] The following comparative foreign matter removal apparatus was prepared in place of the foreign matter removal apparatus 1000A, and the irradiated pellicle assembly was obtained in the same manner as in Example 1 except that the gas supply step was not performed. The comparative foreign matter removal apparatus was the same as in Example 1 except that the gas supply unit 3 was not provided. Figure 1 The foreign matter removal apparatus 1000A shown in the figure has the same structure. When the irradiation step is performed, the oxygen concentration is 21 volume % and the nitrogen concentration is 79 volume %.

[0250] [3] Example 2

[0251] The irradiated pellicle was obtained in the same manner as in Example 1 except that the following second pellicle was prepared in place of the first pellicle and the composition of the inert gas atmosphere was changed to the composition shown in Table 1.

[0252] [3.1] Preparation process

[0253] The second pellicle membrane assembly was produced as follows.

[0254] While N2 gas is flowing, a MoSi film of less than 100 nm is formed on a silicon substrate by CVD (chemical vapor deposition). Afterwards, the silicon substrate is etched from the side opposite to the side on which the MoSi film is formed to form a self-supporting film of the MoSi film. "Self-supporting film" refers to the area of ​​the MoSi film that is not supported by the silicon substrate. Thus, a second protective film assembly is prepared.

[0255] The second pellicle assembly comprises a second pellicle assembly frame obtained by etching a silicon substrate and a second pellicle composed of a MoSi film. The second pellicle is supported by the second pellicle assembly frame. The second pellicle covers an opening of the second pellicle assembly frame. The thickness of the second pellicle is less than 100 nm. The size and material of the second pellicle assembly frame are the same as the size and material of the first pellicle assembly frame.

[0256] [4] Comparative Example 2

[0257] Instead of foreign matter removal apparatus 1000A, the comparative foreign matter removal apparatus described below was prepared, and the irradiated pellicle was obtained in the same manner as in Example 2 except that the gas supply step was not performed. During the irradiation step, the oxygen concentration was 21% by volume, and the nitrogen concentration was 79% by volume.

[0258] [5] Example 3

[0259] A third pellicle assembly having the same structure as the second pellicle assembly was prepared in the same manner as in Example 2. The third pellicle assembly was prepared in place of the second pellicle assembly, the composition of the inert gas atmosphere was changed to that shown in Table 1, and the illumination was set to 66 mW / cm2 , except for this, the same operation as in Example 2 was carried out to obtain an irradiated pellicle assembly.

[0260] [6] Comparative Example 3

[0261] The irradiated pellicle assembly was obtained in the same manner as in Example 3 except that the comparative foreign matter removal apparatus described below was prepared instead of foreign matter removal apparatus 1000A and the gas supply step was not performed. During the irradiation step, the oxygen concentration was 21% by volume and the nitrogen concentration was 79% by volume.

[0262] [7] Example 4

[0263] The irradiated pellicle was obtained in the same manner as in Example 1 except that the fourth pellicle assembly described below was prepared in place of the first pellicle assembly.

[0264] [7.1] Preparation process

[0265] The fourth pellicle assembly was produced as follows.

[0266] As a plurality of CNTs, a plurality of single-walled CNTs synthesized by the eDIPS method (manufactured by Meijo Nanocarbon Co., Ltd., trade name: "EC1.5-P", tube diameter: 1 nm to 3 nm, tube length: 100 nm or more) were prepared.

[0267] To 30 mg of multiple CNTs, 70 mL of isopropanol and 30 mL of ethanol were added, and 30 mg of polyacrylic acid was further added as an additive. The mixture was stirred at 40°C for 18 hours at 1000 rpm (revolutions per minute) using a magnetic stirrer. The resulting suspension was ultrasonically dispersed for a total of 30 minutes using a probe-type homogenizer at an output power of 40% to obtain a CNT dispersion.

[0268] An 8-inch silicon wafer (hereinafter referred to as a "silicon substrate") was prepared. The CNT dispersion was spin-coated on the silicon substrate at a rotation speed of 1500 rpm. Thus, a coating film formed on the silicon substrate was obtained.

[0269] The coated film was alkali-washed with tetramethylammonium hydroxide (hereinafter referred to as "TMAH") to remove the polyacrylic acid in the unwashed CNT film, and then dried to obtain a CNT film.

[0270] Hereinafter, the silicon substrate and the CNT film formed on the silicon substrate are collectively referred to as a "silicon substrate with a film".

[0271] The silicon substrate with the film is immersed in a water bath. In the water, the CNT film is peeled off from the silicon substrate. The CNT film peeled off from the silicon substrate is left in the water, and the silicon substrate is taken out of the water. At this time, the CNT film floats on the water surface. Thus, a fourth protective film composed of a CNT film having a mesh structure is obtained.

[0272] A fourth pellicle assembly frame having the same size and material as the first pellicle assembly frame is prepared. The third silicon frame is a cylindrical object. The third silicon frame has a through hole, and the through hole is formed along the thickness direction of the third silicon frame.

[0273] The CNT film is washed with water to remove the polyacrylic acid in the CNT film and then dried. Next, the silicon substrate with the CNT film is immersed in water. In the water, the CNT film is peeled off from the silicon substrate and floats on the water surface. The CNT film is left in the water and the silicon substrate is removed from the water. The CNT film floating on the water surface is scooped up using the third silicon frame. Thus, the fourth protective film assembly is obtained.

[0274] The fourth pellicle assembly includes a third pellicle assembly frame and a third pellicle composed of a CNT film. The third pellicle is supported by the third pellicle assembly frame. The thickness of the third pellicle is less than 50 nm. The size and material of the third pellicle assembly frame are the same as those of the first pellicle assembly frame.

[0275] [8] Evaluation

[0276] [8.1] Membrane rupture evaluation

[0277] The pellicle of the pellicle assembly after irradiation was visually confirmed, and the membrane rupture evaluation was performed according to the following criteria. As Reference Example 1, the first pellicle assembly placed before the stage 12 was also evaluated in the same manner. As Reference Example 2, the second pellicle assembly placed before the stage 12 was also evaluated in the same manner. As Reference Example 3, the third pellicle assembly placed before the stage 12 was also evaluated in the same manner. As Reference Example 4, the fourth pellicle assembly placed before the stage 12 in Example 4 was also evaluated in the same manner. The evaluation results are shown in Table 1.

[0278] A: No rupture of the protective film

[0279] B: The protective film has been broken

[0280] [8.2] Foreign matter determination

[0281] The amount of foreign matter attached to the pellicle of the treated pellicle assembly was measured by the following method. As Reference Example 1, the same measurement was performed on the first pellicle assembly before being placed on the stage 12. As Reference Example 2, the same measurement was performed on the second pellicle assembly before being placed on the stage 12. As Reference Example 3, the same evaluation was performed on the third pellicle assembly before being placed on the stage 12. As Reference Example 4, the same measurement was performed on the fourth pellicle assembly before being placed on the stage 12 in Example 4. The measurement results are shown in Table 1.

[0282] An optical microscope (OLYMPUS; MX series) was used to capture an image of 142.70 mm × 110.25 mm at 5x magnification and 3.69 μm × 3.69 μm per pixel. The image was used to measure the number of foreign particles. The entire image was analyzed using the calculation software included with the optical microscope to determine the number, size, and type of foreign particles.

[0283] It should be noted that foreign matter with a size exceeding 5 μm to 10.5 μm cannot be confirmed. The maximum size of foreign matter that the device can detect is 1 μm.

[0284] The “size of foreign matter” means the size after detecting foreign matter within the image range of X: 320 μm, Y: 740 μm, and calculating and calibrating each foreign matter as an ESD (equivalent circle diameter).

[0285] [8.3] Transmittance

[0286] Using EUV-RT (Reflection and Transmission), the protective film was irradiated with a wavelength of 13.5nm, and the current value was measured. In detail, a photodiode was used to measure the current value (incident light intensity I0) detected in the state where the protective film was not set and the current value (transmitted light intensity I) detected in the state where the protective film was set. In the measurement of the current value (transmitted light intensity I), the entire protective film surface was divided into 48 parts, and the current value (transmitted light intensity I) of each part was measured. The transmittance of each part is calculated by the following formula (1), and the average value is taken as the transmittance. As a reference example 1, the same measurement was performed on the first protective film assembly before being placed on the stage 12. As a reference example 2, the same measurement was performed on the second protective film assembly before being placed on the stage 12. As a reference example 3, the same evaluation was performed on the third protective film assembly before being placed on the stage 12. As a reference example 4, the same measurement was performed on the fourth protective film assembly before being placed on the stage 12 in Example 4. The measurement results are shown in Table 1.

[0287] [Number 1]

[0288] Tr=I / I0 (1)

[0289] [Table 1]

[0290]

[0291] In Table 1, the foreign matter measurement item "1 μm to 5 μm" means that the 1 mm thickness of the pellicle membrane 2 The number of foreign particles with a size of 1 μm to 5 μm in the area of ​​​​the protective film. The "≤10.5 μm" item of the foreign particle measurement item means that the 1mm 2 The number of foreign matters with a size of 10.5 μm or more in the area. "-" in the foreign matter measurement item means that the number of foreign matters could not be measured due to the rupture of the protective film. "-" in the gas supply process and irradiation process items means that the gas supply process and irradiation process were not implemented. "≤98" in the nitrogen concentration item means that the nitrogen concentration is 98 volume % or more.

[0292] The gas supply step was not performed in Comparative Examples 1 to 3. When the irradiation step was performed, the oxygen concentration in the irradiation chamber 10A was 21% by volume. As a result, the film rupture evaluation of the comparative examples was "B".

[0293] This result shows that the pellicle membrane manufacturing method of the comparative example cannot prevent the occurrence of pellicle membrane damage.

[0294] In Examples 1 to 4, the gas supply process and the irradiation process are implemented simultaneously. When the irradiation process is implemented, the oxygen concentration in the irradiation chamber 10A is less than 5 volume % (specifically, 0.6 volume % in Example 1 and less than 0.01 volume % in Examples 2 to 4). As a result, the film rupture evaluation of Examples 1 to 4 is "A". Furthermore, the number of foreign matter measured in Example 1 is less than the number of foreign matter measured in Reference Example 1. The number of foreign matter measured in Example 2 is less than the number of foreign matter measured in Reference Example 2. The number of foreign matter measured in Example 3 is less than the number of foreign matter measured in Reference Example 3. The number of foreign matter measured in Example 4 is less than the number of foreign matter measured in Reference Example 4.

[0295] From these results, it can be seen that the method for producing the pellicle membrane of the example can prevent the pellicle membrane from being damaged and can remove foreign matter adhering to the pellicle membrane.

[0296] The disclosure of Japanese Patent Application No. 2022-140279 filed on September 2, 2022 and the disclosure of Japanese Patent Application No. 2023-047154 filed on March 23, 2023 are incorporated into this specification by reference in their entireties.

[0297] All documents, patent applications, and technical standards described in this specification are incorporated into this specification by reference to the same extent as if each document, patent application, and technical standard was specifically and individually described as being incorporated by reference.

Claims

1. A foreign matter removal device, comprising: a vacuum ultraviolet light generating unit for generating vacuum ultraviolet light, an irradiation container for irradiating the protective film with the vacuum ultraviolet light, and a gas supply unit for supplying an inert gas to the irradiation container; The irradiation container has an irradiation chamber, and a gas supply port for supplying the inert gas and a gas exhaust port for exhausting the inert gas are provided in the irradiation chamber; The gas supply unit is connected to the gas supply port.

2. The foreign matter removal device according to claim 1, wherein: A transmission portion for transmitting the vacuum ultraviolet light is further provided at a boundary between the irradiation chamber and the vacuum ultraviolet light generating portion. 3 . The foreign matter removal device according to claim 1 , further comprising a stage disposed in the irradiation chamber and for mounting the pellicle membrane.

4. The foreign matter removal device according to claim 1, wherein: The inert gas includes nitrogen.

5. The foreign matter removal device according to claim 1, wherein: The cumulative light intensity of the vacuum ultraviolet light is 0.1 J / cm 2 ~100J / cm 2 .

6. The foreign matter removal device according to claim 1, wherein: The illumination of the vacuum ultraviolet light is 5mW / cm 2 ~100mW / cm 2 .

7. The foreign matter removal device according to claim 3, further comprising a transmission portion for transmitting the vacuum ultraviolet light at a boundary between the irradiation chamber and the vacuum ultraviolet light generating portion, The irradiation container further includes a distance adjustment portion that adjusts the distance between the transmission portion and the stage.

8. The foreign matter removal device according to claim 1, wherein: The gas exhaust port is arranged at a position lower than the center of the irradiation chamber in the height direction of the irradiation chamber.

9. The foreign matter removal device according to claim 8, wherein: The gas supply port is arranged at a position higher than the center of the irradiation chamber in the height direction of the irradiation chamber.

10. The foreign matter removal device according to claim 1, wherein: The irradiation chamber has two opposite wall portions. The gas supply port is disposed on one of the two opposing wall portions. The gas exhaust port is disposed on the other of the two opposing wall portions.

11. A pellicle assembly manufacturing device, comprising the foreign matter removal device according to any one of claims 1 to 10.

12. A method for manufacturing a protective film, comprising: supplying an inert gas into the irradiation chamber, and In an inert gas atmosphere in an irradiation chamber, the protective film is irradiated with vacuum ultraviolet light; In the irradiation chamber, the oxygen concentration in the inert gas atmosphere is 5 volume % or less.

13. The method for manufacturing a pellicle membrane according to claim 12, wherein: In the irradiation chamber, the oxygen concentration is 3 volume % or less.

14. The method for producing a pellicle membrane according to claim 12 or 13, wherein: The inert gas includes nitrogen.

15. The method for producing a pellicle membrane according to claim 12 or 13, wherein: The flow rate of the inert gas is 10 L / min to 1000 L / min.

16. The method for producing a pellicle membrane according to claim 12 or 13, wherein: The cumulative light intensity of the vacuum ultraviolet light is 0.1 J / cm 2 ~100.0J / cm 2 .

17. The method for producing a pellicle membrane according to claim 12 or 13, wherein: The illumination of the vacuum ultraviolet light is 5mW / cm 2 ~100mW / cm 2 .

18. The method for producing a pellicle membrane according to claim 12 or 13, wherein: The irradiation time of the vacuum ultraviolet light is 1 second to 30 minutes.

19. The method for manufacturing a pellicle membrane according to claim 12 or 13, wherein the irradiation chamber has a transmission portion at a boundary of the irradiation chamber for transmitting the vacuum ultraviolet light. The separation distance between the permeable portion and the protective membrane is 0.3 mm to 2.0 mm.

20. The method for manufacturing a pellicle assembly according to claim 12 or 13, wherein: The protective film has a thickness of 100 nm or less.

21. A protective film assembly comprising: Protective film assembly frame, and a protective film supported on the protective film assembly frame; The protective film has a film thickness of less than 100 nm, The protective film contains foreign matter with a size of 1 μm to 5 μm, The number of the foreign matter is 35 or less.

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